Backend Protocol

Standard Channel since v1.2.0

This concept has been part of the Standard Channel since v1.2.0. For more information on release channels, refer to our versioning guide.

Not all implementations of Gateway API support automatic protocol selection. In some cases protocols are disabled without an explicit opt-in.

When a Route's backend references a Kubernetes Service, application developers can specify the protocol using ServicePort appProtocol field.

For example the following store Kubernetes Service is indicating the port 8080 supports HTTP/2 Prior Knowledge.

apiVersion: v1
kind: Service
metadata:
  name: store
spec:
  selector:
    app: store
  ports:
  - protocol: TCP
    appProtocol: kubernetes.io/h2c
    port: 8080
    targetPort: 8080

Currently, Gateway API has conformance testing for:

• kubernetes.io/h2c - HTTP/2 Prior Knowledge
• kubernetes.io/ws - WebSocket over HTTP